Thrombosis is the abnormal clotting of blood in blood vessels, the process of activating the release of pro-coagulant substances, resulting in the massive aggregation of platelets and the formation of clumps. The formation of thrombosis is mostly related to changes in hemodynamics, such as reduced blood flow velocity and viscous blood. The clinical manifestations are mostly swelling of the limbs, but the skin temperature is elevated, sometimes accompanied by pain at the extremities. The thrombus is curable, and the disease itself is not serious, but the acute disease caused by the thrombus is very serious, such as the pulmonary embolism caused by the dislodgement of the deep vein thrombus in the lower limbs. When the stable thrombus is small, it can be treated with local braking or systemic anticoagulation, and the change of thrombus can be observed dynamically. If the unstable thrombus or the thrombus is large, surgery should be performed to avoid the thrombus from dislodging and forming pulmonary embolism, which is mostly done by lower cavity filter implantation. Thrombosis can be prevented and cured, and the prognosis is better. When suffering from thrombosis, there is no need to panic and go to regular hospital vascular surgery in time.